Someone on another forum suggested eco-complete (I just changed my gravel this week in my 55 gallon so I too can have live plants). It works great, looks fantastic, and doesn't cloud up the water when you put it in!
Also, set aside a lot of time to change the gravel. I had two fish in my tank when I changed it, so I drained 75% of the water, scooped out all the gravel, added 65 lbs of new gravel (enough to cover the bottom of my tank 3"), and then put new water in... I started at 10 pm (when I got home from work) thinking it would take me about two hours. I didn't finish until 3 am. So yeah, plan ahead and save yourself from going to bed way too late when you have work in the morning
